Deer may be a reservoir host for SARS-CoV-2
Following a USDA study showing that 40% of white-tailed deer in the USA had antibodies against Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), researchers tested the hypothesis that infection and subsequent transmission of SARS-CoV-2 of deer occurs in nature.
In a study posted on the pre-print server bioRxiv, yet to be peer-reviewed, a total of 283 retropharyngeal lymph node samples recovered from wild and captive deer in Iowa between April 2020 and January 2021 were tested for SARS-CoV-2 viral RNA using a real-time reverse transcription polymerase chain reaction assay. This method provides direct evidence of infection with the virus.
One third of all samples tested positive, with the percentage of deer testing positive increasing throughout the study. The researchers say the findings suggest that white-tailed deer may be a reservoir for the virus to continually circulate.
“This is the first direct evidence of SARS-CoV-2 virus in any free-living species, and our findings have important implications for the ecology and long-term persistence of the virus,” said Suresh Kuchipudi, Huck Chair in Emerging Infectious Diseases, clinical professor of veterinary and biomedical sciences, and associate director of the Animal Diagnostic Laboratory at Pennsylvania State University.
The team also sequenced the complete genomes of all the positive samples from the deer and identified 12 SARS-CoV-2 lineages, with B.1.2 and B.1.311 accounting for about 75% of all samples. The geographic distribution and nesting of clusters of deer and human lineages suggest multiple spillover events from humans to deer, followed by deer-to-deer transmission.
The researchers say there is an urgent need to implement a more proactive and robust One Health approach to better understand the ecology and evolution of SARS-CoV-2 in deer and other free-living species.
Chandler, J. C., Bevins, S. N., Ellis, J. W., Linder, T. J., Tell, R. M., Jenkins-Moore, M., Root, J. J., Lenoch, J. B., Robbe-Austerman, S., DeLiberto, T. J., Gidlewski, T., Kim Torchetti, M., Shriner, S. A. (2021). SARS-CoV-2 exposure in wild white-tailed deer (Odocoileus virginianus). Proceedings of the National Academy of Sciences of the United States of America, 118(47), e2114828118, doi: 10.1073/pnas.2114828118
Kuchipudi, S. V., Surendran-Nair, M., Ruden, R. M., Yon. M., Nissly, R. H., Nelli. R. K., Li, L., Jayarao, B. M., Vandegrift, K. J., Maranas, C. D., Levine, N., Willgert, K., Conlan, A. J. K., Olsen, R. J., Davis, J. J., Musser, J. M., Hudson, P. J., Kapur, V. (2021). Multiple spillovers and onward transmission of SARS-CoV-2 in free-living and captive white-tailed deer. bioRxiv 2021.10.31.466677, doi: 10.1101/2021.10.31.466677
[SOURCE: Pennsylvania State University]